The present invention relates generally to methods and systems for material characterization and more particularly, to methods and systems for characterizing drilling fluids laden with LCM (Lost Circulation Material) and other solid materials.
Drilling operations play an important role when developing oil, gas or water wells or when mining for minerals and the like. During the drilling operations a drill bit passes through various layers of earth strata as it descends to a desired depth. Drilling fluids are commonly employed during the drilling operations and perform several important functions including, but not limited to, removing the cuttings from the well to the surface, controlling formation pressures, sealing permeable formations, minimizing formation damage, and cooling and lubricating the drill bit.
When the drill bit passes through porous, fractured or vugular strata such as sand, gravel, shale, limestone and the like, the hydrostatic pressure caused by the vertical column of the drilling fluid exceeds the ability of the surrounding earth formation to support this pressure. Consequently, some drilling fluid is lost to the formation and fails to return to the surface. This loss may be any fraction up to a complete loss of the total circulating drilling fluid volume. This condition is generally known in the art as Lost Circulation. Failure to control Lost Circulation increases drilling cost and can damage formation production capabilities.
The general practice is to add any number of materials to the drilling fluid which act to reduce or prevent the outward flow of the drilling fluid in a porous and or fractured stratum thereby reducing or preventing Lost Circulation. The materials used in this process are commonly referred to as Lost Circulation Materials (“LCM”). Some materials typically used as LCM include, but are not limited to, wood fiber, popped popcorn, straw, bark chips, ground cork, mica, ground and sized minerals and the like.
In order to better understand the performance of a drilling fluid laden with LCM and/or other solid materials on the field, it would be desirable to characterize and study the drilling fluid. Currently, such tests are performed in the field. Field test are currently centered on the standard API configured HTHP filtration device. In this device the user can select porous media of various pore throat sizes. In some instances a flat plate with a slotted gap(s) has been used. However, performing such tests on the field has several disadvantages.
One disadvantage of the current approach is that the drilling fluid cannot be analyzed in detail since the analysis will be limited to the existing equipment such as the existing slot widths and angles. Moreover, performing such analysis in the field would be expensive and time consuming.
While embodiments of this disclosure have been depicted and described and are defined by reference to example embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.